1. Field of the Invention
The present invention relates to a thin film transistor and a method for manufacturing a thin film transistor. In particular, the present invention relates to a method for manufacturing a thin film transistor having a bottom gate-top contact structure including an organic semiconductor device and a thin film transistor obtained by this method.
2. Description of the Related Art
In recent years, a thin film transistor (TFT) including an organic semiconductor as a channel layer, that is, so-called an organic TFT, has been noted. The organic TFT has an advantage in cost reduction because a channel layer including an organic semiconductor can be formed through coating at low temperatures. In addition, formation can be conducted on a flexible substrate, e.g., plastic, exhibiting poor heat resistance. Regarding such an organic TFT, it is in the public domain that deterioration of characteristics due to a stress, e.g., heat, is suppressed by employing a bottom gate-top contact structure as compared with a bottom contact structure.
In production of the above-described organic TFT having the bottom gate-top contact structure, a method for patterning a source electrode and a drain electrode on an organic semiconductor pattern with high precision has been considered. For example, Japanese Unexamined Patent Application Publication No. 2006-216718 discloses a method for forming a source electrode and a drain electrode, wherein a transverse member is disposed dividing a space above a substrate into two, an organic semiconductor pattern is formed through evaporation from two directions and, thereafter, a metal material is evaporated in such a way as to divide with the transverse member.